UNIT 1.5 ATOMIC STRUCTURE AND ELECTRON CONFIGURATION
Chemistry is the study of matter and interactions. Chemistry overlaps with many other sciences.
Below is the contents for this sub unit. This will allow you to jump to any section you desire. If you have taken Chemistry 1, this should all be review but it is always good to brush up on the basics (significant figures especially).
ATOMIC STRUCTURE
Instead of recreating the structure of the atom material here, I'm just putting a link to the Chem 1 History of the Atom page
ELECTRON CONFIGURATION
Again, this is review. See Orbitals and Electron configuration page from Chem 1.
COULOMB'S LAW
Coulomb's law is used to calculate the force between two charged particles, so in an atom we are looking at the positive charge of the core and the negative electron in the orbitals.
​
F (is proportional to) q1 x q2 / r^2
​
F is the force. q1 and q2 are the charge on the 2 particles. r is radius (which is squared).
​
So looking at the formula, larger atoms will have a more positive core, and thus a stronger pull.
​
Also the further away from the core (radius increases) the less force there is.
​
SO: It is easier to pull electron off an atom that are in the outer ring.
QUANTUM NUMBERS
In order to keep track of electrons, a system of 4 quantum numbers were introduced.
​
So lets talk about the electron configuration of hydrogen
​
So the first quantum number is the principle quantum number - n, and it is the energy level
​
The quantum number is the angular momentum - L (usually cursive L)
0 - s
1 - p
2 - d
3 - f
​
The magnetic quantum number (m sub L) can be -L to + L including 0
0 for s
-1, 0, 1 for p
-2, -1, 0, 1, 2 for d
-3, -2, -1, 0, 1, 2, 3 for f
It's the number of orbitals
​
The spin quantum number is either + 1/2 or - 1/2 for the up or down electrons from the box formation (opposite spin - remember each orbital shape can hold 2 electrons)
​
We'll that's easy the H is 1s2 so
n = 1, l = 0, ml = 0, and ms = + or - 1/2
Yup that one is easy
Now do the last electron in Al
Do the electron configuration first [Ne] 3s2 3p1
So the possible quantum numbers are
n l ml ms
3 2 -1 + or - 1/2
3 2 0 + or - 1/2
3 2 1 + or - 1/2
​
Now imagine doing a d or f orbital. The possible numbers get long. However remember the rules from the picture and that is usually a way to remember what is possible.
​
​